Osteoprotegerin/receptor activator of nuclear factor kappa-B/receptor activator of nuclear factor kappa-B ligand and the application of relevant target therapy in oral medicine / 中国组织工程研究

BACKGROUND:Osteoprotegerin(OPG)/receptor activator of nuclear factor-κB(RANK)/receptor activator of nuclear factor-κB ligand(RANKL)are important cytokines for coupling osteoclast and osteoblast differentiation and activation,and are key factors for regulating bone metabolism,which affect the immune system,bone regeneration and remodeling,and are closely related to the physiological and pathological remodeling of the alveolar bone. OBJECTIVE:To analyze the effects of the OPG/RANK/RANKL signaling pathway on alveolar bone remodeling and the progress in its targeted therapy application in the dental field. METHODS:We searched relevant articles included in CNKI and PubMed databases with the keywords of"OPG,anti-RANKL antibody,RANKL,periodontitis,orthodontic tooth movement,implant,tooth eruption,periapical lesion,alveolar bone resorption"in Chinese and English,respectively.A total of 63 articles were finally included for review. RESULTS AND CONCLUSION:Anti-RANKL therapy can treat oral diseases by targeting the inhibition of osteoclast formation and alveolar bone absorption.Local and systemic anti-RANKL therapy can inhibit the progression of periodontitis,peri-implantitis and periapical lesions,and it also plays an important role in preventing orthodontic relapse,strengthening orthodontic anchorage and implant osseointegration.RANKL therapy can treat oral diseases by promoting osteoclast differentiation and alveolar bone absorption.RANKL treatment can accelerate orthodontic tooth movement,shorten the treatment cycle and reduce the incidence of orthodontic complications.Although there are limitations in anti-RANKL therapy,they can be avoided by rational applications,such as excluding local and systemic risk factors before treatment,regular oral maintenance and avoiding traumatic alveolar surgery as much as possible during treatment.

Effect of Jingui Shenqiwan on Diabetic Osteoporosis in Mice via AGEs/RANKL/NF-κB Pathway Based on Theory of "Kidneys Governing Bones" / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Jingui Shenqiwan on diabetic osteoporosis （DOP） in mice by regulating the advanced glycation end products （AGEs）/receptor activator of nuclear factor-κB ligand （RANKL）/nuclear factor-κB （NF-κB） signaling pathway based on the theory of "kidneys governing bones". MethodForty 6-week-old male and female skeletal-muscle-specific， dominant negative insulin-like growth factor-1 receptor （MKR） mice were selected and fed on a high-fat diet for eight weeks to establish the DOP model. The model mice were randomly divided into a model group， low- and high-dose Jingui Shenqiwan group （1.3， 2.6 g·kg-1）， and an alendronate sodium group （0.01 g·kg-1）， with 10 mice in each group. Additionally， 10 FVB/N mice of the same age were assigned to the normal group. The corresponding drugs were administered orally to each group once a day for four weeks. After the administration period， fasting blood glucose （FBG） measurement and oral glucose tolerance test （OGTT） were conducted. Kidney function and kidney index were measured. Renal tissue pathological changes were observed through hematoxylin-eosin （HE） and Masson staining. Immunohistochemistry was performed to assess the protein expression levels of AGEs， phosphorylated NF-κB （p-NF-κB）， and RANKL in renal tissues. Western blot analysis was conducted to measure the expression of proteins related to the AGEs/RANKL/NF-κB signaling pathway， osteoprotegerin （OPG）， and Runt-related transcription factor 2 （RUNX2） proteins in femoral bone tissues. ResultCompared with the normal group， mice in the model group exhibited significantly increased FBG （P<0.01）， trabecular bone degeneration， abnormal bone morphological parameters， significantly increased area under the curve （AUC） of OGTT （P<0.01）， enlarged kidney volume， significantly increased kidney function indicators and kidney index （P<0.01）， disrupted renal glomeruli and renal tubule structures， significantly increased expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues （P<0.05）， and significantly decreased expression of OPG and RUNX2 in femoral bone tissues （P<0.01）. Compared with the model group， mice in the Jingui Shenqiwan groups showed a significant decrease in OGTT AUC （P<0.01）. Histopathological analysis revealed alleviated structural lesions in renal glomeruli and renal tubules. Furthermore， the expression of AGEs， RANKL， and p-NF-κB/NF-κB in renal tissues was significantly reduced （P<0.05， P<0.01）， and the expression of RUNX2 and OPG in femoral bone tissues was significantly increased （P<0.05， P<0.01）. ConclusionJingui Shenqiwan can improve kidney function and downregulate the AGEs/RANKL/NF-κB signaling pathway to inhibit inflammatory reactions， thereby alleviating the symptoms of DOP in mice， demonstrating a therapeutic effect on DOP from the perspective of the kidney.

Association of serum sRANKL and Omentin-1 levels with bone mineral density and bone metabolism in postmenopausal osteoporosis patients / 中华内分泌外科杂志

Objective:To investigate the relationship between serum soluble receptor activator of nuclear factor-κB ligand (sRANKL), Omentin-1 levels and postmenopausal osteoporosis (PMOP) .Methods:A total of 310 menopausal patients admitted to Qingdao Municipal Hospital from Jun. 2017 to Jul. 2021 were selected, including 165 patients with PMOP and 145 women with simple menopause as the control group. Serum sRANKL and Omentin-1 levels were detected by ELISA. Bone mineral density and bone metabolism indexes [N-terminal propeptide of typeⅠprecollagen (PINP), bone alkaline phosphatase (BALP), β isomer of the C-terminal telopeptide of type Ⅰ collagen (β-CTX) and osteocalcin (OC) ] were compared between the two groups. The correlation between serum sRANKL and Omentin-1 levels and bone mineral density and bone metabolism indexes in PMOP patients was analyzed by Pearson. The predictive value of sRANKL and Omentin-1 to PMOP was analyzed by ROC curve. Logistic regression analysis of the influence of multiple factors on PMOP.Results:Compared with the control group (15.62±4.41) (42.56±8.53), the serum sRANKL level (26.63±8.12) was increased and Omentin-1 level (32.32±5.52) was decreased in PMOP group ( t=14.55, P<0.001; t=12.69, P<0.001). The serum sRANKL in PMOP group was positively correlated with PINP, β-CTX and OC, while the serum Omentin-1 level was negatively correlated with the above indexes by Pearson analysis. ROC curve showed that serum sRANKL and Omentin-1 had important reference significance in predicting PMOP. Logistic regression suggested that increased sRANKL and decreased Omentin-1 were risk factors for PMOP. Conclusion:Serum sRANKL and Omentin-1 in patients with PMOP are correlated with bone mineral density and bone metabolism, and have potential as diagnostic targets of PMOP.

Effects of low-level laser on the expression of interleukin-6, tumor necrosis factor‑α, osteoprotegerin, and receptor activator of nuclear factor-κB ligand in human periodontal ligament cells / 华西口腔医学杂志

OBJECTIVES@#This study aims to determine the effects of low-level laser (LLL) on the expression of interleukin-6 (IL-6), tumor necrosis factor (TNF)-α, osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) in human periodontal ligament cells (HPDLCs) stimulated by high glucose; and identify the molecular mechanism of LLL therapy in the regulation of periodontal inflammation and bone remodeling during orthodontic treatment in diabetic patients.@*METHODS@#HPDLCs were cultured in vitro to simulate orthodontic after loading and irradiated with LLL therapy. The cultured cells were randomly divided into four groups: low glucose Dulbecco's modification of Eagle's medium (DMEM)+stress stimulation (group A), high glucose DMEM+stress stimulation (group B), hypoglycemic DMEM+LLL therapy+stress stimulation (group C), and hyperglycemic DMEM+LLL therapy+stress stimulation (group D). Groups C and D were further divided into C1 and D1 (energy density: 3.75 J/cm2) and C2 and D2 (energy density: 5.625 J/cm2). Cells in groups A, B, C, and D were irradiated by LLL before irradiation. At 0, 12, 24, 48, and 72 h, the supernatants of the cell cultures were extracted at regular intervals, and the protein expression levels of IL-6, TNF-α, OPG, and RANKL were detected by enzyme-linked immunosorbent assay.@*RESULTS@#1) The levels of IL-6 and TNF-α secreted by HPDLCs increased gradually with time under static pressure stimulation. After 12 h, the levels of IL-6 and TNF-α secreted by HPDLCs in group A were significantly higher than those in groups B, C1, and C2 (P<0.05), which in group B were significantly higher than those in groups D1, and D2 (P<0.01). 2) The OPG protein concentration showed an upward trend before 24 h and a downward trend thereafter. The RANKL protein concentration increased, whereas the OPG/RANKL ratio decreased with time. Significant differen-ces in OPG, RANKL, and OPG/RANKL ratio were found among group A and groups B, C1, C2 as well as group B and groups D1, D2 (P<0.05).@*CONCLUSIONS@#1) In the high glucose+stress stimulation environment, the concentrations of IL-6 and TNF-α secreted by HPDLCs increased with time, the expression of OPG decreased, the expression of RANKL increased, and the ratio of OPG/RANKL decreased. As such, high glucose environment can promote bone resorption. After LLL therapy, the levels of IL-6 and TNF-α decreased, indicating that LLL therapy could antagonize the increase in the levels of inflammatory factors induced by high glucose environment and upregulate the expression of OPG in human HPDLCs, downregulation of RANKL expression in HPDLCs resulted in the upregulation of the ratio of OPG/RANKL and reversed the imbalance of bone metabolism induced by high glucose levels. 2) The decrease in inflammatory factors and the regulation of bone metabolism in HPDLCs were enhanced with increasing laser energy density within 3.75-5.625 J/cm2. Hence, the ability of LLL therapy to modulate bone remodeling increases with increasing dose.

The osteoprotective effects and mechanisms of RA model mice by total saponins of Chaenomeles speciosa / 中国药房

OBJECTIVE To study the osteoprotective effects and possible mechanism of total saponins of Chaenomeles speciosa on rheumatoid arthritis （RA） model mice， and to provide reference for further development of anti-RA drugs. METHODS Seventy male DBA/1 mice were randomly divided into normal group， model group， low-dose and high-dose groups of C. speciose total saponins （60， 240 mg/kg）， Tripterygium wilfordii polyglycoside tablets group （positive control， 30 mg/kg）， with 14 mice in each group. In addition to the normal group， the other groups of mice were induced by glucose-6-phosphate isomerase mixed polypeptide to prepare RA model. The body weight， rear toes thickness and arthritis scores of each group were recorded； the synovial inflammation， bone and cartilage destruction of ankle joint tissues were observed by hematoxylin-eosin staining， tartrate- resistant acid phosphatase staining and safranin O-fast green staining； the contents of interleukin-6 （IL-6） in serum and tumor necrosis factor α （TNF-α）， IL-4 and IL-10 in ankle joint tissues were detected by ELISA； the expression levels of receptor activator of nuclear factor-κB ligand （RANKL）， receptor activator of nuclear factor-κB （RANK）， osteoprotegerin （OPG）， tumor necrosis factor receptor-associated protein 6 （TRAF6） and nuclear factor of activated T cells 1 （NFATC1） protein in ankle joint tissues were detected by Western blot assay. RESULTS At the end of administration， compared with normal group， the body mass of mice in the model group was significantly reduced （P＜0.05）， and the arthritis score and the thickness of the left and right rear toes were significantly increased （P＜0.05）； the ankle joint tissues of mice in the model group showed significant synovial proliferation and inflammatory infiltration， the number of osteoclasts increased significantly and significant destruction of cartilage tissue. The content of IL-6 in serum， the content of TNF-α， the protein expression levels of RANKL， RANK， TRAF6 and NFATC1 in the ankle joint tissues were increased significantly （P＜0.05）， while the contents of IL- 4 and IL-10， the protein expression level of OPG in the ankle joint tissues were decreased significantly （P＜0.05）. Compared with model group， above pathomorphological changes and the content/level of indicators of mice in each administration group were significantly improved （P＜0.05）. CONCLUSIONS Total saponins of C. speciosa may exert osteoprotective effects on RA model mice， the mechanism of which may be associated with reducing the contents of IL-6 and TNF-α， increasing the contents of IL-4 and IL-10， inhibiting the activation of RANKL/RANK/OPG signal pathway， thus inhibiting the proliferation of osteoclasts and promoting the repair of cartilage and bone tissue.

Traditional Chinese Medicine Intervenes in Signaling Pathways Associated with CKD-MBD： A Review / 中国实验方剂学杂志

Traditional Chinese medicine （TCM） has certain advantages in the treatment of chronic kidney disease-mineral and bone disorder （CKD-MBD）. In recent years， there have been many studies on the treatment of CKD-MBD by Chinese medicinal compounds and monomers. As revealed by literature retrieval， the research on the mechanism of Chinese medicine in intervening in signaling pathways related to CKD-MBD was mainly based on self-made Chinese medicinal compounds， and the action pathways involved fibroblast growth factor 23/Klotho （FGF23/Klotho） signaling pathway， Wnt/β-catenin signaling pathway， receptor activator of nuclear factor-κB/receptor activator of nuclear factor-κB ligand/osteoprotegerin （RANK/RANKL/OPG） system， and other signaling pathways. TCM can improve calcium and phosphorus metabolism and bone metabolism disorder， and regulate inflammatory reaction， oxidative stress， apoptosis， and autophagy by regulating this series of signaling pathways for the treatment of CKD-MBD. This paper introduced the research results of these signaling pathways and the mechanism of TCM in the treatment of CKD-MBD in order to provide ideas and references for the related research of Chinese medicine in the treatment of CKD-MBD.

Effect of daidzein on OPG and RANKL expression in human osteoblast-like MG-63 cells / 中国药理学通报

Aim To study the regulatory effect of daidzein on osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) expression in MG-63 cells and its mechanism. Methods RT-PCR, Western blot and siRNA were used to study the regulatory effect of daidzein on OPG and RANKL expression in human osteoblast-like MG-63 cells. Results Daidzein could promote the expression of OPG mRNA and protein in MG-63 cells and inhibit the expression of RANKL mRNA and protein, which could be blocked by ICI 182780. It was confirmed that ERa and ER0 mediated not only the promoting effect of daidzein on OPG expression of MG-63 cells but also the inhibition of RANKL. Conclusions Daidzein promotes OPG gene expression in MG-63 cells and inhibits the expression of RANK gene expression through ERa and ERβ pathways.

Differences of B cells, plasma cells, and related cytokines expression in gingival tissues between periodontitis and periodontal healthy subjects / 华西口腔医学杂志

OBJECTIVE@#This study aimed to compare the differences of B cells, plasma cells, and related cytokines expression in gingival tissues between periodontitis and periodontal healthy subjects.@*METHODS@#Gingival tissues were collected from periodontal healthy subjects (periodontal healthy group, n=12) and periodontitis patients (periodontitis group, n=15). Hematoxylin-eosin (HE) staining was used for histopathological examination. Immunohistochemical staining (CD19, CD38, and CD138) was applied to detect the expression of B cells and plasma cells. B cell-activating factor (BAFF) and soluble receptor activator of nuclear factor-κB ligand (sRANKL) were detected by enzyme-linked immunosorbent assay.@*RESULTS@#Extensive inflam-matory cell infiltration was found in the gingival tissues of the periodontitis group. The number of CD19(+), CD38(+), and CD138(+) cells of the periodontitis group was significantly higher than that of the periodontal healthy group (P<0.000 1). BAFF and sRANKL levels of the periodontitis group were higher than those of the periodontal healthy group (P<0.01, P<
0.001, respectively).@*CONCLUSIONS@#The expression of B cells, plasma cells, and their related BAFF and sRANKL cytokines were significantly higher in periodon-titis patients than those in the periodontal healthy subjects, sug-gesting that B cells and plasma cells may be involved in the development of periodontitis.

Mechanism of participation of osteocytes in the formation of osteoclasts under hypoxia / 华西口腔医学杂志

OBJECTIVE@#To investigate the mechanism of the participation of osteocytes in the formation of osteoclasts under hypoxia.@*METHODS@#The hypoxia culture system of osteocyte-like cell line MLO-Y4 was established by deferoxamine mesylate (DFO) in vitro. The proliferation of MLO-Y4 cells was examined by CCK-8 cell proliferation/toxicity assay. RAW264.7 cells were induced to osteoclasts by the conditioned medium containing the cultured MLO-Y4. Tartrate-resistant acid phosphatase (TRAP) staining was performed on day 7. Quantitative real-time fluorescence polymerase chain reaction, immunofluorescence, and Western blot were used to detect the expression levels of hypoxia-inducible factor (HIF)-1α and receptor activator of nuclear factor-κB ligand (RANKL) in MLO-Y4 under hypoxia. The effects of siHIF-1α on the expression levels of HIF-1α and RANKL in MLO-Y4 under the same conditions were detected.@*RESULTS@#DFO (100 μmol·L⁻¹) promoted the proliferation of MLO-Y4 at 24 h, which decreased with time (P<0.01). After the addition of soluble sRANKL, the formation of osteoclasts was significantly increased in the DFO group (P<0.001). The expression of RANKL mRNA in MLO-Y4 under 100 μmol·L⁻¹ DFO increased first and then decreased with the duration of hypoxia. This expression reached a peak at 24 h (P<0.01). Hypoxia up-regulated the expression of HIF-1α and RANKL protein (P<0.01). Under hypoxia, siHIF-1α downregulated the expression of HIF-1α and RANKL (P<0.01). siHIF-1α also decreased the number of osteoclasts (P<0.01).@*CONCLUSIONS@#Under hypoxia, MLO-Y4 could facilitate the formation of RANKL through upre-gulating the expression of HIF-1α protein, thereby accelerate the differentiation of RAW264.7 cells into osteoclasts.

Risedronate inhibits rat bone marrow adipogenesis and reduces RANKL expression in adipocytes / 南方医科大学学报

OBJECTIVE@#To investigate the effects of risedronate on bone marrow adipogenesis and the expression of the receptor activator of nuclear factor κB ligand (RANKL) in adipocytes in the bone marrow micro-environment.@*METHODS@#Primary cultured rat mesenchymal stem cells (BMSCs) with or without adipogenic induction for 14 days were treated with 1, 5, 10, and 25 μmol/L risedronate. The droplets of the differentiated adipocytes were analyzed, and Western blotting was performed to detect the expression level of RANKL. Female SD rats (24-week-old) were randomly divided into sham-operated group and ovariectomy (OVX) group, and 12 weeks after the operation, the OVX rats were further divided into control group and risedronate group (2.4 μg/kg, injected subcutaneously for 3 times a week). Eight weeks later, the bone mineral density (BMD) of the rats and bone marrow histopathology of the femurs was examined to evaluate the effect of risedronate on the fat fraction in the bone marrow.@*RESULTS@#Risdronate significantly inhibited adipogenic differentiation of rat BMSCs and suppressed RANKL expression in the adipocytes derived from the BMSCs in a concentration-dependent manner. In OVX rats, risdronate treatment significantly increased the BMD and decreased the fat content in the bone marrow.@*CONCLUSIONS@#Risdronate can effectively inhibit the adipogenic differentiation of rat BMSCs, decrease fat content in the bone marrow, and suppress the generation and function of osteoclasts by down-regulating the expression of RANKL, which can be an important mechanism underlying the therapeutic effect of risedronate against osteoporosis.